Underfeed stoker



J. A. FLEMHNGS UNDEBFEE sToKER Nw 27,1923. @75m Filed May 22', 1920 Y 2 sheets-sheet 1 l .m 6V w l w 2 w E 9 mm1. MM S. A mw w Vv M mmu! D d .Hmmm i w .,mwnu www. Maa 2 w y m Q /M m isi N 1 .Toma n. `risniinuiiies, or SHARON, ianssaciausn'rrs-/assiouon To n. F. sTuncrnvaitvr j o init. oFFicE.

COMPANY, 0F HYDE PARK, MASSACEIUSIl'ETlS,v A CORPORATION OF MASSACHUSTTS.

UNDERFEED STOKER.

Application filed May 22,

To all whom t may concern:

Be itknown that I, JOHN A. FLnMiNGs, a citizen of the United States, residing at Sharon, in the county of N onfolk and State of Massachusetts, have invented certain new and useful Improvements in Underfeed Stokers; and I do hereby declare the follow'- Aing to be a' full, clear, and exact description of the invention, such'as will enable others skilled inthe art'to which it appertains to make and use the same.

The inventionrelates Ato underfeed stokers. rlhe object of'the invention is to -provide i a stokei'iof this character, the parts ot' which are simple and ruggedfin construction and may be economically manufactured and .conveniently assembled or replaced and which, when assembled, are accurately 4maintained in correct relation to eacliother during the continued use of the Stoker.

An important feature of the invention relates to the grate structure which consists of a number of ,unitary grate sections each com.- prisiiig a series of overlapping grate blocks arranged one above the other in step formation upon a grate bar to which they are at-4 tached byl interlocking projections on the blocks vand bars arranged to hold the blocks against outwardl or upward movement with relation to the` bar, each block also being provided with a sto "arranged to prevent inward movement ot the underlying blockA i vandthe'top block being held against inward movement with relation to the bar byacou-v pling such, for instance,- as a pin which connectsthis block to the bar and thus finally locks the series ofblocks vagainst displacement with -relation to each other and to* the bar. cheaply manufactured, are readily assembled and when. assembled are ell'ectively locked againstrelative displacement without the use of numerous securing bolts and the attendant danger ot' working loose or becoming, displaced during continued use of the Stoker.

@ther features of the construction and arrangement ofthe tuyre blocks with relation to the grate sections; to the means for operating the mov.- able grate sections which enables them' to bc readily and accurately assembled in proper relation to each other, and to their operating means; to the mechanism through which the operating meansfor themovable grate :12 sloping awa-y from opposite sides ofthe @he p-arts 'of this structure may bev 'i blocks. The space 'beneath the retort, grates Athe invention relate to.

1920. Serial No. 383,446.

sections is driven; to the constructionof the ash plates which enables them to becheaply and conveniently manufactured .and assembled or replaced; and to various. other constructions and combinations of parts Which contribute to economy in the manufacture and to the durability of the Stoker and to the efficiency of its operation. v

n A' single retort underfeed stoker embodying the 'invention in its preferred form is shown in the accompanying drawings in whit a Fig. 1 is a vertical cross sectional view `showing a'movab-le grate section at th leftv andv a stationary grate section at the right of the retort, Fig 2 is an enlarged detail of one of the vstationary rate sections and overlying ltuyre block, llig. 3 is a plan view of a portion oli'` the fuel supporting structure at the right of the retort in F ig.1, certain parts being omitted to better show the construction beneath, F ig. 4 is a-'plan view partlyv in section showing `the mechan nism foroperating the feed plunger and also the mechanism for operating the movable grate sections, Fig. 5 is a side elevation of `the p-artsshown in F ig.. 4, and Fig. 6 is a perspective view ofa grate bar. h The underfeed Stoker shown in the drawings comprises in general a retort 10, grates retort and ash plates 14, these parts being supported upon vertical supporting niembers'lG 'as'.sliown in Fig. l. The gi'ates 12- comprise a plurality' of gratesections, each consisting of angrate'bar 19 carrying a series of grate blocks-23. Tuyre blocks 25 are arranged along the sides ot" the retort and are supported upon the sides of the retort and upon the tops of the upper grate lvided with heads 37 which rest side by side upon the top of one of the inner supports 16 and maintain the upper ends of the bars in proper spaced relation. The inner ends 9 of the heads 'are `closed and in connection *with the closed inner ends ot' the upper grate blocks completely lill the space betweenzthe upper end ,of the support andthe bottoms of the tuyre blocks and form a part of the dividing wall which separatesthe aii' supply bars in proper spacedl relation. The feet of the stationary grate bars' are provided with l depending flanges' 4()7 40 embracing thevertlcal suppnrt 16 tolprevent ,movement of the lower ends of thesepgra'te bars with relation to the support., lThe feet of thennovable 20 faee of thesupport 16.

grate bars have no flanges. andare. free to slide forward and back 'over the upper surl Eachg'rate section is a unitary structure consisting ofthe grate bar '19 and-thevs'eries y of overlapping grate blocks 23 arranged one above the other in step formation and. inter locked with 4the bar and with each other.

Each4grate block consists of atop plate provided .with a depending flange whichext'ends v along the side edges and around the-curved front en d of the plate' andV forms alwall, the lower edge of which is adaptedto rest' upon the top plate of .the underlying. block. An

enclosed passage is thus formed 'between the top plates leading to the air ports at the vfront ends of 'the blocks. The top plate ot' each grate block, except the top block; is

provided with a central Slot extending-forward from its-inner end "so that the block may stra-ddlethe grate bar and bev supported ywith one-or `more depending hooks'BO which face outward and are arrange-d tot engage interlocking relation to the bar. lThe lowerv of the. ash plate 14.

7o ,y outer end ofthis grate block 'and thetop'*- The tuyre blocks 25 resty upon theJ` upper i surfaces of the upper grate blocks 'of both the stationary and movable grates and also '75- up'onthe sides of the retort 10. Each tuyre .block is provided with'a depending hook 42 adapted-.to hook under a flange 44 project'- vthereby hold Vthe tuyre `block atitsinner ing from theI top of the side of the'retort to side from upward movement.4 .Provision is I madefor'locking the tuyre-blocks' tothe grate bars and for this purpose thegratev barof each stationary grate is provided with a hook 48 extended l upwardly .therefrom @through slots 49, 5.1 in the top of the upper.`

grate block and bottom ofthe' tuyre block., respectively. The hook- 48l is adaptedlt'o -hook over a'crss bar 46-of the tuyre block, l

lEach tuyreblock is'ofsuflicient lengthv to j extend partially across tl'i'e-` movable fgrates' on each side-of the stationary 4grate so that the joints between the adj acentv tuyre blocks are located-over the midport'ions of the up-v per grate blocks of the`;m0 vable grates." The Y tuyre'blocksin this manneroperate toprevent upward movement lof' 'the inner ends 'of the movable grates andat the same time per-v mit reciprocation of themovable grates.

In assembling the grate sections the lowei` grate block of. each is placed Iupon the vplate f 36 supportedon the feet 38with the hooksv 3() hooked under .the lugs 32. lEach succeed- ;with the hooks 3() hooked under the lugs 32 and 'with the inner end `of the top. lofeacli grate blocl'supported. on the Ilugs 24.' As `each succeeding 'grate block is 4placed .in 15osit-ionlv the stop lugs 34 depending 'therefrom lugs 32 projecting from' opposite. sides ofy lock the-underlying grate block in placeyand the bar 19v andthus lock the block against upwardand outward movement with rela-v tion to the bar; Each block isalso-piovided with a stop for engaging the inner end fof the underlying block andv locking itv against inward movement so that the interlocking hooks`and lugsA are held against disengagement. On all of the blocks except the top" the correspondingl top grate block thel lowerv block the stops'are formed by projections 34 on the hooks 3.0. On the topblock theystops are formed byA lugs 41 on theside :walls of upon the headv 37; of thev Iqratebar and formsA a continuation of the-closed inner end of;

the head. `VA c oupli'ngjin the form of a pin 43 connects the upper block to the' grate-bar and finally locks all of thegratej blocltSin *over thesides oli. the vertical supportl.y

prevent .inward movement thereof. l

In this manner all of the` intermediate end of eachstationary 'grate section is lift:

ed and moved outwardlyv until thegh'ook 48 flange 44 and lowered. onto the upper grate' `block, the hoolf48 passing upy through the slot 51. The' grate section is then moved inthe' foot ofthe'grate bar is droppedin place ing grateblock is theny pla-ced'y in position',-

wardlvthereby hooking the hoolt 48 over the cross bar 46' and the flanged end upon i in i movement upwardly about the inner edge of the tuyre block as a fulcrum.. y

With this construction the grate structure includingthe grate bar, `grate blocks and tuyre blc'k is bound together and positively held against displacement except in an`up= ward direction, while an upward movement of any of the grateV sections involves swing-' ing the grate structure up about the inne-r edgelof the tuyre block as a .fulcrum and consequently lifting of the grate-structure and the charge of the fuel thereon. There is no danger,n therefore, vthat the devices f crank disk 90 is adjustably secured by bolts 80 which engage and reciprocate the movable i gratefsectionswill lift and displace the grate or grate sections in case of unusual resistance to the movement of the vgratesections due to the sticking of the grates or other causes. Neither is there any danger that any part of the grate will be displacedl by the use of a bar to break up any clinkers which may form.

In the operation of the Stoker, theV coalis fed by mechanical for other means' into a hopper 50 which communicates with the 1 forwardl end of the retort 10. A power driven plunger 52 feeds the coal lengthwise of the retort from which it is gradually moved laterally over the grates to the 'as h plates. The plunger 52 is actuated from a driven shaft 54 through a crank 56 and connecting rod 58. -The connecting Y rod may be provided with a, safety device indicated at 59 constructed to give way should the forward movement of the plunger tbe unduly Vresisted andI thereby avoid injury to the Vplunger or its operating mechanism. y

Provision is made for reciprocating alternate grate bars .in order toassist in the movement of the coal from the retort to thev ash plates, and for this purpose each grate bar 19 of the. movable grates is provided with a depending rack 7 64 arranged to meshwith an operating segment V'78 mounted upon a rock shaft 80 extended lengthwise of the Stoker uponA each side of the retort 10. The segment and rack 76, 78 are provided with an enlarged locating tooth 7.7 and tooth space 79 respectively which enable them to be pro rly positioned with relation to one anot er. Each operating segment 78 is Amounted upon and removably secured to the rock shaft 80 in suchy manner that any particular segment may v"be removed without the removal ofthcflemaining segments. To this end', each segment`78 is provided with a yokel94 adaptedl to be slipped directly over the rock shaft` 80. The segment 78 is secured upon the bar rock shaft by a locking block 96 which is received within the yoke and. held in place by the flanged-ends v98 of-the yoke be held in .place lengthwise of theshaft by any suitable means. The rock shaft is preferably of hexagonal shape, as shown' in F ig. 1. Each rock shaft -80 is actuated from the power driven plunger operating mechanism through a rockerV shaft 82 con- 75 nected'therewith through bevelled gears 84 (see F 4) and through an'arm 8 6, link l 88V, and crank disk 90 upon the end ofthe vplunger operatingcrank shaft 54. lThe 92 to the flanged end of a hub 93 secured upon the endof the crankshaft 54.' The lheads of the bolts 92 arereceived in recesses in the crank disk, as 4shown in Fig. 5.

a The. movements ofthe crankdisk are 85 transmitted to the link 88 through a crank pin 102 slidably received in a slot 104 in the link. A nutj106 'and washer 108 hold the link in -lace, and a block 110 affords adjustment o the amount of-lost motion between 90 the crank disk and link.

As previously described, the rack `an segment 76, 78 are provided with. an enl larged. tooth 77 and tooth space 79, to enable their position with .relation to one another to be definitely established and maintained. The bevel gears 84 upon the rock shafts 80'and the rocker shaft 82 respec- -tively,are also each provided with an enlarged tooth andtooth space 81, 83 so that a 100* `'definite relation may be established between the ventire bar operating train. As only a few teeth inthe-bevel gears 84 are neces- Sary to vgive therequired motion to the 'grates, the gears'fare divided into four sections, vany of whiic'h may be utilized by shifting the gears on the shafts 80 and 82,A as shown in Figi y5,. The ends of both the rockershaft 82 and rock shafts 80 are 1 squared to receivel and' correctly position the 1.10

gears 84. l Provision is made for reciprocating a. pusher rod 112 which extends through the retort. The end of the pusher rod 112 is,

and rod.`

extended through a hole in the end of the l vIn the voperation of the Stoker, the coal vis burned in the retort 10 and upon the grates 12. The lashes are received upon ash plates 14 provided vwith chisel-shaped outer edges which operate to cut the clinker 14 is supported upon and securedl to a sup-A porting plate 120.'- Thev inner end of each ash plate has two lugs 122 adapted to pro-V ject under the'top of a curved flange 123 on when the plates are rocked4 Each ash plate' 125 the inner end jof theSupporting Platei lao The outer endof each'ash plate. is secured by two bolts 1.24- to thezsupporting plate. The ash plates and supporting plates .are mounted upon squareshafts 126. For this 5 purpose eachlsupporting plate 120 is provided-with .a square openbearin adapted to enablev the supportin plate to e slipped directly over the square s aft 126. A .bottom l plate 132l closesthe open bearing and holds ,10 the supportingplate fast upon the shaft'126, l

being secured-to the supporting plate by bolts 1,34.. The square shafts' 126. are supported at their ends sleeves 136,h'aving. square Aopenings adapted toenable'thesleeves t0 be' -lgslipped over the ends'of the square shafts. The vsquare shafts 126' vaire supported 4at points intermediate theirfends by open collarslil adapted to be slippedlaterallyonto the 'shafts' and to." be thereafter positioned lengthwise .thereof.1 TheI collars 144' are supported inope'n bearings v148. in brackets 150l bolted to the` vertical support- 16, as

shown iny Fig. 1.` The squareshafts 126'v are' adapted tov be turned tov dump the ash plates bythe manual 'rocking of counter-v shafts 138 geared to the square' shafts by A bevelled gearsv139. Short'socket.a'rmafl40,v

. adapted to receiveabar-or yother tool, are

'mounted up'on the counter-shafts 138*- and lafford `convenient meansffor dumping the'y hoding.

ash plates.v llnrovisi'onis made for the ash plates in any desired angular position, and for this purpose apa'wl 142is pro-v .videdl which engages a ratchet. 143 upon f lfeach countershaft 138,` as shown in Fig; 4-

lVhile-the preferred embodiment. of the invention has been illustrated.,andl described,` it will-be understood that lthe in- -vention vmay be embodied in other forms 47' within the scope ofthe following claimsz-f 1. A girate section `comprisin'ga grate bar, :a plura 1 ty of overlapping grate. blocksv "mounted thereon, one end of each block being- .supported -on the 'upper surface '.43 'ofthe underlying" block, lugs on the bar for'supporting thev other endsof the blocks', depending hooks onI thev blocks, lugs on: the :bar 'withwhiclrthe hooks engage Vto holdV the upper grate blocks ofthe grate sections having a slot and-'acrossbar in the bottom thereof, and a .hook extended from'v the sta.

tionary grate `loar through said slot. and hooked'oversaid.` cross bar.y 70 .Y 4..An underfeed Stoker' having, in'combination,v aretort, a .plurality of grate. sections extending laterally therefrom, each .grate section comprisinga rate bar supported at its opposite en' s, andl grate blocks arranged thereon in stepsv so that the sides and .one end of veach overlying block are supported-on`theupper surface'of the p underlying block,.3lugs on ea/ch grate bar on `which the other'ends of the grate blocks are fsupported, dependinghooks onthe blocks, v

the blocks from movement awa ,fr mj thev Athe hook v@ml cooperating lug ofthe under? lying blockin engagement. v

2. A grate` sectionA comprising an inclined v v grate/ bar, a series ofl horizontal overlapping '50 bar, anda stop oneach .block -or holding'L fbination, a retort and a grate'extendinglat# .tween lthe tuyre blocks and grate blocks,

andlugs on thev bar'. withwhich the hooks `engage vvto prevent movement ,of the 4blocks away 'from the, bar. 5. An underfeed Stokerl having,.in combination, a .retort and -a plurality of grate sections extending laterallytherefrom, each grate' section comprising agrate bar', a plu- `rality of grate;A .blocks Aarranged in ste s, upon-the grate bar and provided with hoo (s for securing themv 'to'the bar, andv a plurality. of tuyref-blocks each'supported atone .side upon `the 'uppergrate blocks and at the other side.4 uponV the retort, linterlocking members onl the reto'it'and tuyere. blocks,'and interlocking members-on` the grate sections and tuyerejblocks. l

i6. yAn underfeed' stokerjhaving, incornerally-from thefupper edge of the retort comprising la plurality'v offgrate bars,l a se` ries.' offgrate blocks mounted upon each grate bar, interlocking members `for bind? l ingY the blocks onthe bars, tuyre 'blocks yalong the4 edge ofA the retort, eachof which 195 v'o'verlies a plurality of grate blocks-,inten locking members vbetweenethe retort, and tuyre blocks, and .interlocking members bewhereby. displacement ofl any portion of the 110 grate vinvolves the upward vswinging ofthe grate'structure about the edge ofthe retort.'

7. An underfe'ed Stoker having; in combination, a retort; a'grate to .which .fuel is fed from the retort consistingof grate sections, each comprising any inclined grate bar; a

kseries of.l1orizontal grate ,blacks arranged 5'. grate blocks slotted to straddle the bar, in-

'laterally therefrom,4 Vja wall along the thereon,.interl0cking members lformed on the bloelrsfandbar for locking-the blocks to i 4the bar, and a stop on each block for liold- .120 ing the underlying block in interlocking relation' to the bar.-v

8. An underfeed stoker having, in .coinylbinationa retort, a grate to which fuel is fed from the retort consisting ofv grate sections, each Icomprising a grate bar, a series ofy o-rate blocks arranged thereon in'steps, eacli block comprising atop plate slotted at its rear end to straddle the bar and project o icoI the blocks and bar for lockingthe blocks tol the bar, and a stop on each block for holding the underlying block -in interlocking relation to the bar. Y Y

10. An underfeed Stoker having in combination, a retort, a grate to which fuel is fed from the retort consisting of grate sections, each comprising a grate bar, a series of grate blocks arranged thereonin steps, each block comprising a top plate slotted at itsV rear end to straddle the bar and a wall along its sides and front end adapted 'to rest onthe underlying block, hooks on'y the blocks, lugs on the sides of the bar for supporting the rear ends ofthe blocksand for engaging the hooks, and a stop on each block for'engaging the rear end of the underlying block.

11. An underfeed Stoker having, in combination, a retort, a grate to Which fuel is -fed from the retort' consistin each comprising a grate bar having a spaeing head fat one end and a spacing foot at the other, 'a series of grate blocks arranged -on the bars in steps, each block comprising plate slotted at its rear end to straddle a to y the bar and a wall alon its sides and front end adapted to rest on t e underlyin block,

a plate on the foot on which 4the ottom block rests, means-for'securing the blocks on the bar, and atop block having an/unslotted top plate and a closed inner end and an air chamber under the grate.

12.` An underfeed Stoker havin ,in combination, a retort, a series of inc med grate bars at the side of the retort, spacingheads having closed ends at the upper ends of the bars, spacing feet'at the lower ends of the bars, supports for the head and feet forming the walls of'anair chamber below the bars, a

series of (grate blocks secured' to each `bar in steps an includin a top block lhearing a closed end registering with-the end of the spacing head and tuyre blocks bridging the space between the retort and the top grate blocks. :f

13. An underfeed stoker having, in combination, -a retort, movable and stationary grate sections extending therefrom, each of 'which comprises a grate bar and a series of' grate blocks secured thereon, and Vtuyre blocks, each of which is secured to the side of the retort and to the end ofl astationay grate section and overlies the ends of the a jacent movable sections. f t

14. An underfeed stoker having, in combi'- of grate sections,

nation, a retort, movable and stationary grate 1sections extending therefrom, each of whlch comprises a grate 'bar and a series ot grate blocksl secured thereon, tuyre blocks Wall, an. air chamber lon each side of the wall, a series of grate bars having spacing and forming a continuation-of said dividing wall, a series of grate blocks on each bar the end block of which has a closed end forming' a continuation of saidA Wall, and

heads supported side by side on the support' 'tuyre blocks bridging the space between the side of the retort and blocks.

16. An under/feed Stoker having, in come bination, a retort, two sup-ports at the side of thel retort forming'the walls of an air said' end lgrate chamber, grate bars .having spacing heads and feet supported side'b side on the supports. a series of grate blocks Asecured on each bar, the end block of which has a closed en d forming with the closed ends of the heads a continuation of one wall of the chamber, and` tuyre blocksl bridging the space between the side of the retort and said closed end blocks.

17. An underfeed stoker having, in combination, a retort, two supports at the side of the retort formingthe Walls of an air chamber, grate bars having spacing heads andrfeet supported side by side onth'e supports, a series of grate blocks secured on each bar, the end block of which has a closed Vend forming with the closed ends of the heads a continuation of one wall-of. the chamber, tuyre' blocks bridging the space between the side of the retort and said closed ended blocks, and mechanism forre-v ciprocating some of the grate bars. Y 18. A stoker having, in combination, a retort, a plurality of grate bars, a plurality vof grate blocksfmounted thereon, .and means for moving lsome of the grate bars including a rock shaft, cooperating racks and se lments on the movable grate bars and sha respectively, each segment having a yoke adapted to be slipped laterally over the shaft, and a block adapted to tit into the yoke to lock the yoke and segment in fixed relation to the shaft whereby any segment may be removed from the shaft Without disv turbingthe remaining segments or grate its i and meansv for moving vsomeoi` the-.grate segment.having an abnormal locating tooth v15 v and. cooperating bevelled gearsfon each,'the

mente, each beingprovided lwith an -alonor-4 y bars including. a rock shaftand coopeia'tf ing'ack's and segments-g 'on the movable grate barsand-shaft'respeotively, leach seg- 1 ment having provision whereby it may be re-` moved .from the shalt without disturbing l shaft, a rock shaftgeared tolthe,v rocker the remaining segments.V i

1 20. .An underfeed stokerhaving, in 'Com-1 i bi'nation," aretort, a plurality of grate bars, 10

andmeans forv movin Someof .the-grate bars includingr al roc shaft," `cooperating racks and segments .on the'inovable grate bars and shaft respectively, .each 'rack and and tooth space whereby the grate bars are' positioned yWith relation tov eachother, and means for 'operating'the rock shaftl includ# ingl a rocker shadtand gears'on the rock shaft and rocker shaftv respectively vhav-ingv anabnorm'al tooth and tooth spacewhereby the relation between the` 'operating means and grate bars'is determinedy.' ,21. yAn underfeed. Stoker-lg'avingj im combination, a retort, a, pluralityl of. grate bars,

and means for movl-ng some ofthe grate bars including a rockshaft, arocker shaft,

teeth'on'nsaidl. gears comprising four segmal toothand'tooth space respectively.

and a lin l l '22.-Anunderfeed'stoker having, in combination, a' retort, a: plurality ,of movable onthel shaft-connected t0 operate the plunger, a second crank on the shaft, a rocker shaft, eooperating segments on -the rock shaft and rates, an arm on the rocker shaft E connecting vsaid 'arm with ysaid eeconderank.`

"23. An' underfeedlstoker'having, co1n.- `loination, are'tort, a grate extended laterally therefrom, anyash. plate at the outer'en'd of the grate, an ashlAsupportin'g plate to which the'y ashy plate is secured, 4hav-ing an open bearing, a squareshaft upon which the ash supporting plateie mounted, andiabo'tto'ln platebol'ted'to the ash supporting plate and securing thesame tothe Square. shaft. "l 24.' An underfeed Stoker having,l iii comfbin'ation, a retort,- a grate extended' laterally therefrom, an' a$hpl'ate,and lneans'for supporting the ash" nlate including a square shaft, circular en bearings Jfor the. vsquare shaft, open cylindrical collars for embracing intermediatepoints of ythe shaftland openl ,bearingsv in `which said openv cylindrical collarsare supported'.

JOHN A.l 'FLEMINGSL 

